In order to electrically connect conductors of various wires formed of a metal conductor of an inner core and an insulating polymer sheath covering the metal conductor to a conductive pattern of a printed circuit board (PCB), the metal conductor having a circular or tetragonal cross section inside the sheath of the wire, which will be, hereinafter, referred to as a metal core, is exposed outwards and soldered using solder while being in direct contact with the conductive pattern on the PCB or the PCB is perforated and the metal core is inserted into a hole in the PCB and soldered using solder.
As described above, a method of directly connecting a metal core of a wire to a conductive pattern of a PCB using solder has several limitations according to various structure of the PCB.
For example, since a terminal such as a cellular phone is lightened and miniaturized in size to be complicated in an inner structure and to be limited in space, a diameter of a wire used herein is very small. As a result thereof, it is difficult to directly solder a metal core of the wire having a small size to a conductive pattern on a PCB. Particularly, when a size of the conductive pattern of the PCB is small, the strength of soldering between the metal core and the conductive pattern is low.
Particularly, since the PCB has an approximately flat surface, it is difficult to solder with the metal core of the wire.
Also, since the metal core is soldered, it is difficult to attach or detach the metal core to or from the PCB and it is impossible to repetitively attach or detach the metal core using mechanical forces.
In addition, when the metal core of the wire is soldered to a thin and flexible substrate such as a flexible PCB (FPCB) used for the cellular phone, since the substrate has low mechanical strength and is flexible, a soldered portion may be easily cut off.
On the other hand, an electric connector covered with a plastic housing mounted on a PCB may be used. A general electric connector described above is configured by inserting a metal terminal into the plastic housing to be coupled or insert-molding the metal terminal into a housing molding. Accordingly, it is necessary to additionally use the plastic housing, a size of a product increases and manufacturing costs such as additional assembling costs increases.